It is narrated from Sayyiduna Abu Hurairah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "When any of you wishes for something, he should see what he is wishing for, because he does not know what will be given to him."
Hadith Referenceالادب المفرد / كتاب الأقوال / 794
Hadith Gradingالألبانی:ضعيف
Hadith Takhrij«ضعيف : أخرجه أحمد : 8689 و الطيالسي : 2462 و ابن أبى الدنيا فى الميمنيين : 151 و أبويعلى : 5907 - انظر الضعيفة : 2255»