Therefore, remember Me. I will remember you, and be grateful to Me, and never be ungrateful to Me.
Mujahid said that Allah's statement;
كَمَا أَرْسَلْنَا فِيكُمْ رَسُولاً مِّنكُمْ
(Similarly (to complete My favor on you), We have sent among you a Messenger (Muhammad) of your own),
means;Therefore, remember Me in gratitude to My favor.
Al-Hasan Al-Basri commented about Allah's statement;
(Therefore remember Me. I will remember you),
"Remember Me regarding what I have commanded you and I will remember you regarding what I have compelled Myself to do for your benefit (i.e., His rewards and forgiveness)."
An authentic Hadith states;
يَقُولُ اللهُ تَعَالَى مَنْ ذَكَرَنِي فِي نَفْسِهِ ذَكَرْتُهُ فِي نَفْسِي وَمَنْ ذَكَرَنِي فِي مَلٍَ ذَكَرْتُهُ فِي مَلٍَ خَيْرٍ مِنْه
Allah the Exalted said, `Whoever mentions Me to himself, then I will mention him to Myself; and whoever mentions Me in a gathering, I will mention him in a better gathering.'
Imam Ahmad reported that Anas narrated that Allah's Messenger said;
قَالَ اللهُ عَزَّ وَجَلَّ يَا ابْنَ ادَمَ إِنْ ذَكَرْتَنِي فِي نَفْسِكَ ذَكَرْتُك فِي نَفْسِي إِنْ ذَكَرْتَنِي فِي مَلَاٍ ذكَرْتُكَ فِي مَلَاٍ مِنَ الْمَلَايِكَةِ أَوْ قَالَ فِي مَلَاٍ خَيْرٍ مِنْهُ وَإِنْ دَنَوْتَ مِنِّي شِبْرًا دَنَوْتُ مِنْكَ ذِرَاعًا وَإِنْ دَنَوْتَ مِنِّي ذِرَاعًا دَنَوْتُ مِنْكَ بَاعًا وَإنْ أَتَيْتَنِي تَمْشِي أَتَيْتُكَ هَرْوَلَة
Allah the Exalted said, `O son of Adam! If you mention Me to yourself, I will mention you to Myself. If you mention Me in a gathering, I will mention you in a gathering of the angels (or said in a better gathering). If you draw closer to Me by a hand span, I will draw closer to you by forearm's length. If you draw closer to Me by a forearm's length, I will draw closer to you by an arm's length. And if you come to Me walking, I will come to you running.
Its chain is Sahih, it was recorded by Al-Bukhari.
وَاشْكُرُواْ لِي وَلَا تَكْفُرُونِ
and be grateful to Me (for My countless favors on you) and never be ungrateful to Me.)
In this Ayah, Allah commands that He be thanked and appreciated, and promises even more rewards for thanking Him.
Allah said in another Ayah;
وَإِذْ تَأَذَّنَ رَبُّكُمْ لَيِن شَكَرْتُمْ لَازِيدَنَّكُمْ وَلَيِن كَفَرْتُمْ إِنَّ عَذَابِى لَشَدِيدٌ
And (remember) when your Lord proclaimed;"If you give thanks (by accepting faith and worshipping none but Allah), I will give you more (of My blessings); but if you are thankless (i.e., disbelievers), verily, My punishment is indeed severe. (14;7)
Abu Raja' Al-Utaridi said;
Imran bin Husayn came by us once wearing a nice silken garment that we never saw him wear before or afterwards.
He said, "Allah's Messenger said;
مَنْ أَنْعَمَ اللهُ عَلَيْهِ نِعْمَةً فَإِنَّ اللهَ يُحِبُّ أَنْ يَرَى أَثَرَ نِعْمَتِهِ عَلَى خَلْقِه
Those whom Allah has favored with a bounty, then Allah likes to see the effect of His bounty on His creation),
or he said,
"on His servant" - according to Ruh (one of the narrators of the Hadith)