Al-Ala bin Abd al-Rahman (may Allah have mercy on him) said that after finishing the Zuhr prayer he went to the house of Sayyiduna Anas bin Malik (may Allah be pleased with him). His house was right next to the mosque. When we came to him, he asked: "Have you prayed Asr?" We said that we had only just finished offering Zuhr. Hearing this he said: "Go and pray Asr." So we stood up and offered the Asr prayer. When we had finished the prayer, Sayyiduna Anas bin Malik (may Allah be pleased with him) said: I heard the Messenger of Allah (peace and blessings be upon him) say: "That is the prayer of the hypocrite: he sits waiting for the sun until, when it is between the two horns of Satan, he stands up and pecks out four (prostrations), and in it he remembers Allah only a little."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2088