Allah the Exalted says:

“And [remember] Mary, the daughter of ʿImrān, who preserved her chastity; so We breathed into it of Our Spirit” (al-Taḥrīm 66:12).

More than one of the early generations (1) reported that Gabriel blew into the opening of her tunic, whereupon the breath moved down to her private part and she conceived at once, just as a woman conceives through marital intercourse (2). Whoever claims that he blew into her mouth, or that the one who addressed her was a spirit that had entered through her mouth, is contradicting the Qur’anic contexts of this story. For the context clearly shows that the one sent to her was an angel—Gabriel, peace be upon him—and that he blew into her without directly confronting her private part. Rather, he blew into the collar of her garment; the breath then descended to her private part and entered it, as the Almighty said: “so We breathed into it of Our Spirit,” which indicates that the breath entered that part and not her mouth, as is related from Ubayy ibn Kaʿb, nor her chest, as al-Suddī transmitted on the authority of some Companions.

Hence His words: “so she conceived him,” that is, she conceived her son; “and she withdrew with him to a distant place.” When Mary conceived, she felt distressed, knowing that many people would speak against her. Several of the early authorities (3)—among them Wahb ibn Munabbih—relate that when the signs of pregnancy first appeared, the first to notice was a devout man of the Children of Israel named Joseph son of Jacob the carpenter, her cousin. Greatly astonished—given his knowledge of her piety, chastity, and worship—he nevertheless saw her pregnant though she had no husband. One day he hinted at the matter, saying:

“O Mary, can there be a crop without seed?”
She replied, “Yes—who created the very first crop?”
He asked, “Can there be a tree without water or rain?”
She replied, “Yes—who created the very first tree?”
He asked, “Can there be a child without a male?”
She replied, “Yes—Allah created Adam without either male or female.”
He then said, “So tell me your story.”
She answered, “Allah has given me glad tidings of ‘a Word from Him whose name is the Messiah, Jesus son of Mary, held in honor in this world and the Hereafter and one of those brought near; and he will speak to people in the cradle and in maturity, and will be among the righteous’” (Āl ʿImrān 45–46).

A similar account is narrated from Zakariyya—peace be upon him—who questioned her, and she replied in like manner. Allah knows best.

Al-Suddī, with his chain from the Companions (4), narrates that Mary once visited her sister, who said, “I have sensed that I am pregnant.” Mary replied, “I too sense that I am pregnant.” She embraced her, and the mother of John said, “I see what is in my womb prostrating to what is in your womb.” Concerning this Allah said, “confirming a Word from Allah.” Here, prostration means humility and veneration, like the prostration offered in greeting in earlier laws, and like the prostration Allah commanded the angels to perform before Adam.

Abū al-Qāsim said: Mālik remarked, “It has reached me that Jesus son of Mary and John son of Zakariyya were maternal cousins, and that their mothers conceived at the same time. I have been informed that the mother of John said to Mary, ‘I see what is in my womb prostrating to what is in your womb.’” Mālik said, “I hold that to be so.”