as-Saff 61:6, means "Praised One" in Arabic, see also prophesied in the Bible? under MUHAMMAD. Muslims identify this name with Muhammad. Muslims have identified the Comforter metioned in the Bible in John 14 & John 16 that Jesus said he will send to be Muhammad. In order to do that, the Muslims charged that the word for Comforter should not be Paraclete (or Paracletos), but have been changed from the original Periklutos, meaning "Praised One".
However, the Qur'anic verse in question has variants found in other codices that were also in circulation before the Uthmanic codex became standard.
According to Ubayy b. Kab, one of the secretaries of Muhammad, the verse reads: "O children of Israel, I am God's messenger to you, and I announce to you a prophet whose community will be the last community and by which God will put the seal on the prophets and messengers" where "Ahmad" is not mentioned. (See also SEAL OF THE PROPHETS, and for a more detailed discussion of Ubayy's variant refer to Gilchrist.)
This is also attested to by Ibn Ishaq and Ibn Hisham's account of the verse, as recorded in Ibn Ishaq's biography of Muhammad:
"Among the things which have reached me about what Jesus the Son of Mary stated in the Gospel which he received from God for the followers of the Gospel, in applying a term to describe the apostle of God, is the following. It is extracted from what John the apostle set down for them when he wrote the Gospel for them from the Testamant of Jesus Son of Mary: "He that hateth me hateth the Lord. And if I had not done in their presence works which none other before me did, they had not had sin: but from now they are puffed up with pride and think that they will overcome me and also the Lord. But the word that is in the Law must be fulfilled, 'They hated me without a cause' (ie. without reason). But when the Comforter has come whom God will send to you from the Lord's presence, and the spirit of truth which will have gone forth from the Lord's presence he (shall bear) witness of me and ye also, because ye have been with me from the beginning. I have spoken unto you about this that you should not be in doubt."Ibn Ishaq does not say that the word "Paraclete" is "Periklutos". In fact, he confirmed that the word in Greek is Paraclete. Moreover, he affirms that John wrote down the Gospel that was revealed to Jesus. He also used Comforter when translating that word. In order to apply the verse to Muhammad, Ibn Ishaq identifies the Syriac word Munahhemna to Muhammad, instead of using "Ahmad" in both the above passage as well as in as-Saff 61:6, which would be the best (obvious) way to prove that the "Paraclete" is Muhammad.The Munahhemana (God bless and preserve him!) in Syriac is Muhammad, in Greek he is the Paraclete." (Ibn Ishaq, The Life of Muhammad, tr. Guillaume, pp. 103-104)
"The most interesting word is that rendered ‘Comforter’ which we find in Palestinian Lectionary, but all other Syriac versions render it ‘Paraclete’ following the Greek. ... The menahhemana in Syriac means the life-giver and specifally the one who raises from the dead. Obviously such a meaning is out of place here and what is meant is one who consoles and comforts people for the loss of one dear to them." (ibid, Guillaume in footnote)As Guillaume pointed, Muhammad hardly fits the description of one who raises the dead, nor is he a life-giver. When the Syriac Christians applied that title to Jesus, it is perfectly within his authority to give life and raise the dead, as he had demonstrated.
"Muslim children are never called Ahmad before the year 123AH. But there are many instances prior to this date of boys called 'Muhammad.' Very rarely is the name 'Ahmad' met with in pre-Islamic time of ignorance (Jahiliya), though the name Muhammad was in common use. Later traditions that the prophet's name was Ahmad show that this had not always been obvious, though commentators assume it after about 22 (AH) (W.M. Watt who researched the name "Ahmad", as quoted by G. Parrinder, Jesus in the Koran, Sheldon Press, pp. 98-99)
"It has been concluded that the word Ahmad in Quran as-Saff 61:6 is to be taken not as a proper name but as an adjective... and that it was understood as a proper name only after Muhammad had been identified with the Paraclete. (J. Schacht, Encyclopaedia of Islam, Vol I, 1960, p.267)
Note that by the middle of the 2nd century AH, Muslims already identified Muhammad with the Greek word "Paracletos" (Counsellor/ Advocate) or the Aramaic translation "Menahhemana" (New Encyclopaedia of Islam, Vol I, 1960).However, it is only after the middle of the 2nd century AH that Muslims begin to say that the word "Paracletos" should be "Periklutos", and this has been the favourite argument since then. Note the following: In the Syrian Bible translation, the word in dispute is translated as "Paraqlit", and in Arabic it is "Faraqlit", which is very close to be confused. This could the source of confusion among Muslims, but the Greek is very clear.