There is a long prayer of the Prophet mentioned in Musnad Ahmad, al-Tirmidhi and Ibn Majah. One part of this prayer is: رَبِّ اجْعَلْنِي لَكَ شَكَّارًا (Sunan Ibn Majah 3838) It is indeed unique that the Prophet prayed: رَبِّ اجْعَلْنِي لَكَ شَكَّارًا “O God, make me a greatly thankful person!” Shakkar means a person who is very thankful to God. Shakkar has a sense of exaggeration to it. The word shakkar is in the superlative degree. O God, make me a greatly thankful person. This means that the thankfulness desired from people is one in which a person feels deep gratitude. One should become greatly thankful to God. This does not mean that one should endlessly recite the word shukr.

Some people think that they should repeat the word shukr one lakh times. This is not the meaning of Prophet's prayer. It is an underestimation of God to believe that He would be happy if we simply repeat the word shukr. Even a human being won't be pleased with such mechanical thanksgiving. If a collector has a guard at home and the guard continually says Mr Collector, Mr Collector, then that would not please the collector. The collector would be happy if he isn't called out so many times. This happens if you keep chanting his name. The Prophet prayed to God to make him greatly thankful to him. This meant the Prophet asked for the capacity to think and discover items to thank God. From your hair and nails to the solar system and entire galaxies, you should be able to thank God for everything. Your process of thinking should be activated such that you can see reasons to thank God for everything.

This is the meaning of the Prophet's prayer. It has no mysterious or miraculous aspect about it. The Prophet didn't mean to ask God to miraculously make him a thankful person. Thankfulness comes with thinking. The Prophet asked God to make him a deep thinker.