This motet has one of the most challenging textual underlays to set. The chant source is the Graduale Pataviense. It can therefore be surmised that either 1) this motet was composed for the Imperial Hofkapelle, or 2) the Konstanz diocese used the same chant and the motet was part of the Constance commission. Regardless, there are many questionable text placements in the Formschneider print. I have documented the places where I have varied greatly from the source.
Haec dies quam fecit Dominus. Exsultemus et laetemur in ea.
This is the day that the Lord has made. Let us rejoice and be glad in it.