What is the explanation of the hadith, its words, and its jurisprudence, and is there a contradiction in it between the Prophet's innocence from "al-Haliqa" (the shaver) and his action towards the children of the Companion?

The gist of the Hadith is that the Prophet (peace be upon him) gave Ja'far's family three days to mourn Ja'far, without wailing. Then, he shaved the heads of his children out of compassion for them, to protect them from dirt and lice. This does not contradict the Hadith "He is free from every shaver," because shaving the heads of children is permissible, whereas women shaving their heads during a calamity, in objection to Allah's decree, is forbidden.