Hadith 31:112
Da'if (Al-Albani)
'A'isha said, "The Prophet, may Allah bless him and grant him peace, was asked, 'Which type of worship is best?' He replied, 'A man's supplication for himself.'"
حَدَّثَنَا عُبَيْدُ اللهِ، عَنِ مُبَارَكِ بْنِ حَسَّانَ، عَنْ عَطَاءٍ، عَنْ عَائِشَةَ رَضِيَ اللَّهُ عَنْهَا قَالَتْ: سُئِلَ النَّبِيُّ صلى الله عليه وسلم: أَيُّ الْعِبَادَةِ أَفْضَلُ؟ قَالَ: دُعَاءُ الْمَرْءِ لِنَفْسِهِ
Original Reference: Al-Adab Al-Mufrad 715