Katharine Salisbury reported that Joseph could only translate once sins were forgiven.

And when he went to Pennsylvania he commenced translating the book of Mormon, and translated some one hundred and sixteen pages that Martin Harris took home and lost, and when my brother found they were lost, he was very much troubled and said: “I am afraid I have broken the commandments and will not be allowed to translate the record.” The angel came and took the Urim and Thummim from him. He fasted and prayed several days, and the angel returned them again, and told him that his sins were forgiven, and for him to go ahead and translate, but not to translate that that was lost, but to begin where he had left off. He commenced, and when he had got the record partly translated, persecution rose there, and he wrote for David Whitmer to come and take him to his house. David came, and he asked how he should carry the plates and he was told that they would be there when he got there, in the garden. When he got to Father Whitmer’s he found the records, as he had been told he would, and there he finished tra[n]slating the Book of Mormon.See Full