I am no expert, but I have resources (i.e., a large Buddhist library in my home and a laptop).
In the passage you are referring to Lama Tsong Khapa begins by quoting Shantideva, "You should have pride in three areas: action, ability, and afflictions... 'I alone shall do it.'" This is from Bodhi[sattva]caryavatara
7.49. The word in the Tibetan text is apparently nga rgyal
, which carries the negative and positive senses of the word "pride," depending on context. The Sanskrit text reads māna
I have consulted different translations of this verse in Shantideva's text to see what alternatives translators have come up with. B. Alan Wallace and Vesna A. Wallace have "self-confidence." Likewise, Batchelor has "self-confidence." (Padmakara Trans. Group's revised translation reads "pride," as does Crosby & Skilton's version.) In his commentary For the Benefit of All Beings
, His Holiness the Dalai Lama says, "Self-confidence is knowing that one has the ability to do something properly and being determined not to give up."
In addition to "self-confidence," I found that the word has also been translated in a positive sense as "assurance." (See http://rywiki.tsadra.org/index.php/nga_rgyal
at the bottom of the entry.)
I hope this helps.