Tafsir of Maryam 19:49

"So when he withdrew from them and what they worshipped besides Allah..." He abandoned the corrupt disbelievers for the sake of Allah, so He compensated him with believing children who were prophets.

"{Of Our mercy}" According to al-Hasan, this refers to prophethood. According to al-Kalbi, it refers to wealth and children. It may also be general, encompassing every religious and worldly good they were granted.

"A tongue of truth" This means honorable praise. He used the word "tongue" to refer to what is expressed by the tongue, just as "hand" is used to refer to what is given by the hand (i.e., a gift). He said: Verily, a tongue has come to me that does not please me; He means a message. "The tongue of the Arabs" refers to their language and speech. Allah answered his prayer: "And grant me a tongue of truth among the later generations" (Ash-Shu'ara: 84). He made him an exemplar, such that all followers of religions claim him.

The Almighty said: "The religion of your father Abraham" (Al-Hajj: 78), "The religion of Abraham, inclining toward truth" (Al-Baqarah: 135), and "Then We revealed to you: 'Follow the religion of Abraham, inclining toward truth'" (An-Nahl: 123). He granted that to his descendants, elevating their mention and praising them, just as He elevated his mention and praised him.