Behold! the angels said: “O Mary! Allah giveth thee glad tidings of a Word from Him: his name will be Christ Jesus, the son of Mary, held in honour in this world and the Hereafter and of (the company of) those nearest to Allah;
“He shall speak to the people in childhood and in maturity. And he shall be (of the company) of the righteous.”
According to Maariful Quran,
One of the qualities of Sayyidna ‘Isa (peace be upon him) mentioned in this
verse is that ‘he shall speak in the cradle’ which means that he will
speak while still a child, although no child has the ability to do so.
When soon after the birth of infant Jesus, as mentioned in another
verse, people chided Sayyidah Maryam on the basis of a false accusation, this new-born infant, Sayyidna ‘Isa (peace be upon him) spoke up, saying: (I am a servant of Allah). Then following immediately, it was said
that he will also talk to people when he will be in the later middle of
his age (kahl). It is worth noting here that the incidence of speaking in
infancy was certainly a sign and a miracle and it is quite appropriate
to mention it at this point. But, speaking to people during one’s middle
age is very normal, something everyone does no matter whether he is a Muslim, or a non-Muslim, learned or illiterate. Why has this been mentioned here as something special? What could it mean?
One answer to this question appears in Bayan al-Qur’an by Maulana Ashraf ‘Ali Thanavi who says that the real purpose here is to particularly focus on the miraculous nature of meaningful infant speech.
The reference to the speech in the middle age is there to indicate that
his childhood speech too would not be the usual baby talk, rather it
would be rational, even learned and eloquent, as man does in his advanced years. If we were to look into the true historical background of Sayyidna ‘Isa, we would discover that this reference to him as speaking to people in his middle age provides a great standing argument in
favour of the Islamic position which, according to the Qur’anic belief, is
that Sayyidna ‘Isa has been raised alive onto the heavens.
Hadith narrations prove that Sayyidna ‘Isa (peaced be upon him), while so raised,
was in the approximate age bracket of 30-35 years which is youth at
its best. Middle age, kahl in Arabic, was something he never reached
during his life in this world. So, his talking to people in his middle age
can happen only when he were to grace this world once again with his
presence. Therefore, the way his childhood speech was a miracle, his
speech in the middle age could be nothing else but another miracle.
Shafi, Muhammad (2008). Maariful Quran. (Vol .2 surah 3 pg. 71-72). English-MaarifulQuran-MuftiShafiUsmaniRA-Vol-2.pdf (islamicweblibrary.com)