Talmud su Ta'anit 1:8

⁶⁵The parallels are in Ketubot1:1 (Notes 34–42,כ), Ta`aniot4:9 (69b l. 40,ת). Rebbi Abba bar Cohen said before Rebbi Yose: Rebbi Aḥa in the name of Rebbi Jacob bar Idi: A man may not preliminarily marry on a Friday. That means, to make an engagement feast<sup>66</sup>Since this would impinge on the Sabbath meal. It is in order to make the preliminary marriage on Friday and arrange the festive meal as Sabbath meal.. This implies that the preliminary marriage itself is permitted. Samuel says, even on the Ninth of Ab<sup>67</sup>The anniversary of the destruction of both Temples. a preliminary marriage is permitted, lest another forestall him. The argument of Samuel seems inverted. There<sup>68</sup>A similar argument is in the Babli, Mo`ed qaṭan18b., he says, God puts singles in a house; To rise on scales; they all are of vapor!⁶⁹Ps. 68:6, 62:10. This means that marriages are pre-ordained in Heaven. (Lev. rabba29(5).) And here, he says so⁷⁰If marriages are pre-ordained, why should anybody be afraid that another man could snatch the bride preselected for him? Another man might by his prayer cause the Heavenly decree to be changed, but this would lead to the early death of one of the partners of the marriage. Babli Soṭa2a, Sanhedrin22a.? That means, that he should not forestall him in prayer. Even so, it would not be permanent.