عَنِ ابْنِ عَبَّاسٍ رَضِيَ اللَّهُ عَنْهُ أَنَّ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ قَالَ لِرَجُلٍ: ((وَإِذَا سَجَدْتَ فَأَمْكِنْ جَبْهَتَكَ مِنَ الْأَرْضِ حَتَّى تَجِدَ حَجْمَ الْأَرْضِ))
It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said to a man: When you prostrate, place your forehead on the ground in such a way that you feel the solidity of the earth.