“Buli bah kalau kau” is a distinctly Sabahan flavour for the popular local phrase “boleh bah kalau kau”, or “OK bah kalau kau” which can be taken to mean “I concess, especially for you.”
It should be noted that in practice:
- the word “bah” can also be shortened to “ba”;
- the word “kalau” can also be shortened to “kalo”;
- the word “kau” can also be shortened to “ko”.
Like “ini kali lah“, it must have been in use for a long while, but when it comes to being recorded in cyberspace, it seems that this phrase was first written down by a user with handle “ongster” in the popular Sabahan-run forum SabahRhinos.com on 5th May 2005, when he uttered:
Hahahaha, boleh bah kalau kau, kalau Sabah kalah aku belanja kau burger 2 biji, tapi kalau Sabah menang, kau kena bagi aku 5 biji burger, ok.
Entrepreneurs grabbed the opportunity to create T-shirts bearing the phrase in July 2007.
Adam AF released a song of this title apparently sometime in 2010.