It is narrated from Sayyiduna Ka'b bin Ujrah (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: "Whoever gives respite to someone in difficulty, or makes things easy for him, Allah will shade him in His shade on the Day when there will be no shade but His shade."
Hadith Referenceالمعجم الكبير للطبراني / باب الكاف / 16264