It is narrated from Hazrat Abu Huraira (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said: I see behind me just as I see what is in front of me and before me, so keep your rows straight and perform your bowing and prostration well.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 7199