A.T. Robertson Commentary Luke 24:1

"But on the first day of the week, at early dawn, they came unto the tomb, bringing the spices which they had prepared." — Luke 24:1 (ASV)

At early dawn (ορθρου βαθεος). Genitive of time. Literally, at deep dawn. The adjective βαθυς (deep) was often used of time. This very idiom occurs in Aristophanes, Plato, et cetera. John 20:1 adds "while it was yet dark." That is, when they started, for the sun was risen when they arrived .

Which they had prepared (α ητοιμασαν). Mr 16:1 notes that they bought other spices after the sabbath was over besides those which they already had (Luke 23:56).