It is known that ʻAbdu'l-Bahá also sat for portraits at the request of Gibran. From the above, it may be concluded that ʻAbdu'l-Bahá and Gibran knew each other more than in passing, but that ʻAbdu'l-Bahá made no formal or informal claims or suggestions about Gibran's writing but cooperated whenever asked (as for sitting for the drawings.) So the influence is really at the choice of Gibran - he could as well have chosen and mentioned any other source of inspiration for his book. It seems he chose ʻAbdu'l-Bahá. As ʻAbdu'l-Bahá is one of the central figures of the Baháʼí Faith and these are works of fiction, it is certainly the case that at least two of Gibran's, and his most famous, are properly mentioned here.