Plenty of sevens fill this passage,

“And you shall count seven sabbaths of years for yourself, seven times seven years; and the time of the seven sabbaths of years shall be to you forty-nine years. Then you shall cause the trumpet of the Jubilee to sound on the tenth day of the seventh month; on the Day of Atonement you shall make the trumpet to sound throughout all your land” (Leviticus 25.8, 9).

Every seven years the Lord wanted Israel to let the land enjoy a Sabbath.

Then they were to count seven of those seven-year cycles, bringing a total of forty-nine years; then add a year and during that fiftieth year in the seventh month, they observed the Jubilee, during which land reverted back to its original owner, slaves went free, and a few other things.

God loves the number seven, and this event shows His love for seven and His desire for precision and order.