Oculi is the 3rd Sunday of Lent. In Leipzig there is still Tempus Clausum (no music in mass), but luckily 2 cantatas survive from the Weimar period, where Tempus Clausum was not observed.
Although there is discussion if the first cantata (Widerstehe doch der Sünde, BWV 54) was indeed written for Oculi. Others place it at Trinitatis VII (first performance July 15th 1714), but John Eliot Gardiner and others have reason to place it on Oculi of that same year, so it''s Gardiner''s English Baroque Soloists & Monteverdi Choir that perform this cantata for you. This makes this cantata also the first cantata after Bach received his commission in Weimar. It is also his earliest cantata for a solo voice (alto in this case).
The music for the second cantata, Alles, was von Gott geboren, BWV 80a, is lost. But Bach reworked the original score and expanded on it to create his well-known cantata Ein feste Burg ist unser Gott, BWV 80, performed in Leipzig for Reformation Day (October 31st). Because Leipzig had Tempus Clausum, Bach could not re-use the cantata for the same purpose, and so he used it for Reformation Day. Never let a good cantata go to waste, I guess?