The 'Pen of the Most High' learns calligraphy in his childhood!!

Calligraphic exercises by Baha’u’llah in his childhood

Baha'is believe :

Where we must acquire learning, the manifestation possesses innate knowledge. Here we are not referring to knowledge of the revelation itself, which begins at a particular point in the life of a prophet which we have come to associate with some outward sign, such as Moses’ seeing the burning bush, Buddha’s experience under the Bo tree, Christ’s baptism in the Jordan, Muhammad’s visions in the desert, the Bab’s vision of the Imam Husayn, and Baha’u’llah’s vision in the Black Pit of Tehran. Well before they begin their ministries, even during childhood, the prophets demonstrate that they possess a knowledge they have not acquired from any earthly source. In effect, their education is acquired before birth into this physical reality.

https://bahaiteachings.org/prophet-primary-educator

And this is what Baha'u'llah's sister says about him :

The Mirzā (meaning Bahā’u’llāh)...., from the beginning of his life to when he came of age—because the means were at hand and because of the gathering of the companions—was engrossed in studying and endeavored in homework. He wouldn’t disengage from learning the rudiments for a moment. After studying the rudiments of Arabic and literature he inclined towards the science of philosophy (ḥikmat) and mysticism (`irfān) so that he might benefit from these. It was such that he would spend most of the day and night socializing with high statured philosophers and the gatherings of mystics and Sufis. When it was blown in Seraph’s Trumpet of Appearance (meaning when the Bāb made his claims), he (meaning Bahā’u’llāh) was a man who had seen most of the words and phrases of the mystics and philosophers and had heard and understood most of the signs of the appearance (of the Mahdi) . . . after returning from Badasht and after the Shaykh Ṭabarsī Fort war was over, he was engaged day and night in socializing with great Islamic scholars and followers of mysticism . . .

-'Izziye Khānum (Khānum Buzurg), Tanbīh al-nā’imīn, pp. 4–5