It is narrated from Sayyiduna Samurah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "When two guardians give (a woman) in marriage, the first has more right; and when two sellers sell (the same thing), the first has more right."
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 6894