Saeed bin Jubair (may Allah have mercy on him) said that the one who holds the contract of marriage in his hand is the husband.
Hadith Referenceمسند الإمام الشافعي / كتاب الطلاق / 1269
Hadith Takhrijصحیح بشواهده اخرجه البيهقی : / 2517 - وفى المعرفة السنن والآثار له (4326) - وعبدالرزاق (10857)۔ وابن أبي شيبة (16970) - والطبري في تفسيره: (2/ 547، 548)۔
It is narrated from Ibn Jurayj (may Allah have mercy on him) that he received this information from Sa'id bin al-Musayyib (may Allah have mercy on him) that he said: "He is the husband."
Hadith Referenceمسند الإمام الشافعي / كتاب الطلاق / 1270
Hadith Takhrijصحيح بشواهده : اخرجه البيهقي : 251/7 - وفى المعرفة السنن والآثار له (4327) - وعبد الرزاق (10860) ، (10861) وابن ابی شیبة (16973) ، (16980) - والطبري في تفسيره: (2/ 547)۔