In The Name of Allah, The Most Merciful, The Bestower of Mercy.

Allah, The Most High, stated:

لَا تَحۡسَبَنَّ ٱلَّذِينَ يَفۡرَحُونَ بِمَآ أَتَواْ وَّيُحِبُّونَ أَن يُحۡمَدُواْ بِمَا لَمۡ يَفۡعَلُواْ فَلَا تَحۡسَبَنَّہُم بِمَفَازَةٍ۬ مِّنَ ٱلۡعَذَابِ‌ۖ وَلَهُمۡ عَذَابٌ أَلِيمٌ۬

Think not that those who rejoice in what they have done (or brought about), and love to be praised for what they have not done,- think not you that they are rescued from the torment, and for them is a painful torment. [Aal Imran. 188]

لَا تَحۡسَبَنَّ ٱلَّذِينَ يَفۡرَحُونَ بِمَآ أَتَواْ

Think not that those who rejoice in what they have done (or brought about).

Meaning, the rejoicing (accompanied) with insolence and boasting, thinking that they have done a favour to Allah and Allah’s Messenger.

[بِمَآ أَتَواْ – what they have done (or brought about)]- Meaning, the deeds by way of which they seek to get close to Allaah as they claim.

وَّيُحِبُّونَ أَن يُحۡمَدُواْ بِمَا لَمۡ يَفۡعَلُواْ

And love to be praised for what they have not done.

Meaning, they want people to praise them for what they have done, such as feigning righteousness to the people in order to be praised, even if they have not performed an act of righteousness- similar to what the people of the Scripture did, (who) concealed the characteristics of the Prophet, peace and blessings of Allah be upon him, and did not make it known, and then said, “Now we have overcome Muhammad when we say that he is not the Mubash’shar bihee “the Messenger whom Prophet Isa mentioned as the good tidings.

This verse includes two types of people: The people of the Scripture who rejoiced in what they did by concealing the characteristics of the Prophet and not believing in him, and loved to be praised for what they have not done when they pretended to the people that if the Messenger – who is mentioned as good tidings (by Eesaa)- is sent, “We will believe in him”.

The second group are the hypocrites. This is because the hypocrites rejoice in what they do and say, “We have submitted in Islam” in the presence of Muhammad and his companions, whilet their situation is the opposite of that, and they loved to be praised for what they have not done with regards to sincerity, love for Allah and His Messenger, and obedience to Allah’s Messenger.

Source: Tafsir Surah Aal Imran by Imam Muhammad Ibn Salih Al-Uthaymin – may Allah have mercy upon him