3 Many reasons prevented Us up to this time from fulfilling Our wish to write. In the first place, there was what one might call a contest of filial devotion by reason of which there came to us in letters without number the good wishes of Our brothers and children from every quarter of the globe, messages which bespoke a welcome to the newly elected Successor of St. Peter and offered him the well-wishes born of a devoted homage.
Source: Ubi Arcano Dei Consilio (Vatican.va)