Page "Kabir" Paragraph 6

We do know, however, that his early spiritual training came from Ramananda, who became his guru when Kabir was still a child.

There are various versions of how Ramananda came to accept Kabir as his disciple.

What all the versions agree is that Kabir tricked Ramananda into giving him a mantra for meditation, which forced him to accept Kabir as his disciple.