In this popular CNN article, the author raises many arguments to prove that Columbus was a Marrano (hidden Jew), I found none to be very compelling besides for the following one:
At the top left-hand corner of all but one of the 13 letters written by Columbus to his son Diego contained the handwritten Hebrew letters bet-hei, meaning b'ezrat Hashem (with God's help). Observant Jews have for centuries customarily added this blessing to their letters. No letters to outsiders bear this mark, and the one letter to Diego in which this was omitted was one meant for King Ferdinand.
This article is lacking citations, so I tried searching for other sources to corroborate this claim but I wasn't able to. The reason I'm doubting this claim is because if Columbus really wrote these Hebrew letters (an exclusive Hebrew practice) then why are scholars still debating whether Columbus was indeed a Jew, I mean doesn't this prove ipso facto that he was indeed one? How else can we explain the existence of two Hebrew letters on his letters? Why is it brought as a sidenote to the other five non-compelling arguments in the article cited above? Are his letters still in existence today (or at least images of them), is it possible to verify this claim? I mean if I would see those two Hebrew letters with my own eyes, to me that would more than enough proof he was of Jewish origin.