פּירוש אויף ויקרא 4:6

את פני פרכת הקדש [AND THE PRIEST SHALL … SPRINKLE OF THE BLOOD …] BEFORE THE PARTITION VAIL OF THE קדש — i.e. before that spot where it is exceedingly holy — exactly in front of the space between the staves of the Ark (Sifra, Vayikra Dibbura d'Chovah, Section 3 10). The blood did not touch the Partition Vail (since he was standing some distance off), but if it happened to touch it, then it touched it, (and it did not invalidate the ceremony) (Yoma 57a).

The kohen will dip his finger i.e., the High Priest. The significance of seven times is explained in the parasha of Balaq [comment on Numbers 23:1]. Because of the High Priest’s great stature, the blood of his sin-offering is sprinkled in front of the holy Partition, and on the corners of the Incense Altar. All of the bullock, except for the organic fats, is to be burned outside, for it is not a burnt-offering.

וטבל, והזה, “the priest will dip his finger in the blood, and sprinkle;” every sprinkling of the blood has to be preceded by the priest dipping his finger in the blood;