َِوَمِنْهُمْ مَنْ يَسْتَمِعُ إِلَيْكَ حَتَّى إِذَا خَرَجُوا مِنْ عِنْدِكَ قَالُوا لِلَّذِينَ أُوتُوا الْعِلْمَ مَاذَا قَالَ آنِفًا أُولَئِكَ الَّذِينَ طَبَعَ اللَّهُ عَلَى قُلُوبِهِمْ وَاتَّبَعُوا أَهْوَاءَهُمْ ﴿۱۶﴾ وَالَّذِينَ اهْتَدَوْا زَادَهُمْ هُدًى وَآتَاهُمْ تَقْوَاهُمْ ﴿۱۷﴾

﴾16﴿ Wa minhum mai yastami'u ilaika hattaaa izaa kharajoo min 'indika qaaloo lil lazeena ootul 'ilma maazaa qaala aanifaa; ulaaa'ikal lazeena taba'al laahu 'alaa quloobihim wattaba'ooo ahwaaa'ahum
﴾17﴿ Wallazeenah tadaw zaadahum hudanw wa aataahum taqwaahum

﴾16﴿ And among the people are those who listen to you (as spies), but when they leave your presence, they say to those who have been given knowledge, What did he just say, Those are the ones upon whose hearts Allah has set a seal, and they follow their own desires
﴾17﴿ And those who are guided, Allah increases them in guidance and grants them the ability to be mindful (of Him)

[16] This refers to the categorization of the disbelievers—some of them behave in this way, and such behavior is that of a hypocrite.
(مَاذَا قَالَ آنِفًا) – meaning their attention is not on the words of Allah and His Messenger; they are heedless, so they do not understand.
It may refer to a statement they just heard, or to a statement made after they left—which they inquire about as if to say, “What did he say while we were absent?”
Or it could mean that they are not truly heedless, but rather they say it mockingly and with aversion—implying, “What foolish words did this Prophet just say?”
[17] This is in contrast to the two previously mentioned traits of the believers—(زَادَهُمْ): When a believer hears the Qur’an, Allah the Exalted increases his faith because of it.