Read Surah Al-Qasas 28:27: "[After some time, the father] said: “Behold, I am willing to let thee wed one of these two daughters of mine on the unde..." Full Arabic text, English translation, and image generator.
قَالَ إِنِّي أُرِيدُ أَنْ أُنْكِحَكَ إِحْدَى ابْنَتَيَّ هَاتَيْنِ عَلَىٰ أَنْ تَأْجُرَنِي ثَمَانِيَ حِجَجٍ ۖ فَإِنْ أَتْمَمْتَ عَشْرًا فَمِنْ عِنْدِكَ ۖ وَمَا أُرِيدُ أَنْ أَشُقَّ عَلَيْكَ ۚ سَتَجِدُنِي إِنْ شَاءَ اللَّهُ مِنَ الصَّالِحِينَ
[After some time, the father] said: “Behold, I am willing to let thee wed one of these two daughters of mine on the understanding that thou wilt remain eight years in my service; and if thou shouldst complete ten [years], that would be [an act of grace] from thee, for I do not want to impose any hardship on thee: [on the contrary,] thou wilt find me, if God so wills, righteous in all my dealings.”