In one narration the words are: "That I keep reciting the takbir, tahlil and tasbih from true dawn until the sun rises is more beloved to me than freeing four slaves from the descendants of Sayyiduna Isma'il (peace be upon him); and that I keep remembering Allah from the Asr prayer until the sun sets is more beloved to me than freeing such-and-such a number of slaves from the descendants of Sayyiduna Isma'il (peace be upon him)." Ahmad recorded all of these narrations, and al-Tabarani recorded a narration similar to the second one; their chains are hasan (good).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الأذكار / 16937
Hadith Gradingمحدثین:إسنادہ حسن۔
Hadith Takhrij«اخرجه الطبراني فى المعجم الكبير (8028) اخرجه احمد فى المسند (253/5)»