It was narrated by al-Bukhaari in his Saheeh (5255) that Abu Usayd (may Allah be pleased with him) said: We went out with the Prophet (blessings and peace of Allah be upon him) and came to a garden called ash-Shawt; we came to two walls and sat between them. The Prophet (blessings and peace of Allah be upon him) said: “Sit here,” and he went in (to the garden). al-Jawniyyah had been brought and lodged in a house in a date-palm garden in the house of Umaymah bint an-Nu‘maan ibn Sharaaheel, and her maid was with her. When the Prophet (blessings and peace of Allah be upon him) entered upon her, he said: “Give yourself to me (in marriage).” She said: Would a queen give herself to an ordinary man? He stretched out his hand to pat her so that she might calm down, but she said: I seek refuge with Allah from you. He said: “You have sought refuge with One who gives refuge.” Then he came out to us and said: “O Abu Usayd, give her two garments of white linen and take her to her family.”
Why did the Prophet(saw) try to pat a woman who refused to marry him?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad, sallallaahu 'alayhi wa sallam, is His slave and Messenger.

Our Messenger had never laid his hand on a woman who refused to marry him. Rather, he married this woman and divorced her before touching her (consummating the marriage); Allah, The Exalted, did not will for her (to receive) the honor of being among the Mothers of the Believers and the wives of the Prophet, sallallaahu ‘alayhi wa sallam, who will also be his wives in Paradise. What proves that he married her is the Hadeeth cited by Al-Bukhaari on the authority of Sahl ibn Sa‘d and Abu Usayd, who said: “The Prophet married Umaymah bint Sharaaheel, and when she was brought to him, he stretched his hand towards her. It seemed that she disliked that, whereupon the Prophet ordered Abu Usayd to prepare her (for departure) and provide her with two white linen dresses.” Al-Haafith Ibn Hajar established in Fat-h Al-Baari that the term “Al-Jawniyyah” was a reference to Umaymah bint Sharaaheel, and he said: “It is authentically established that her name was Umaymah bint An-Nu‘maan ibn Sharaaheel, as narrated in the Hadeeth reported by Abu Usayd.” [End of Quote] It is authentically reported that he divorced her, and this essentially means that he married her, as divorce cannot occur except after marriage. Therefore, Imaam Al-Bukhaari, may Allaah have mercy upon him, cited the Hadeeth about her in his book Saheeh Al-Bukhaari under the title: “Chapter on the One Who Divorced His Wife, and Whether a Man Can Tell His Wife That She is Divorced to Her Face.” Ibn Hajar said in Fat-h Al-Baari: “Ibn ‘Abd Al-Barr said that they [scholars] unanimously agreed that the Prophet married Al-Jawniyyah, but they differed regarding the reason for the divorce. Qataadah said that when he [the Prophet ] entered upon her, he said to her: ‘Come (to me).’ She replied: ‘You come (to me)!’ Thereupon, he divorced her.” [End of Quote]

For more benefit, please refer to Fatwa 105379.

Allah knows best.