There is an undoubted connection between the record of Samson catching the foxes and using them to destroy vineyards (Jud. 15:4,5) and Song 2:15, where Solomon suggests that he and his girl go and catch the foxes that destroy the vineyards. He seems to have had Samson in mind. And yet both he and his Gentile girlfriend owned vineyards (Song 1:6; 8:11,12), and both were concerned that the fruit would not be damaged (Song 2:13,15; 6:11; 7:12). However, the implication from Solomon's maybe careless allusion was that in fact he was in the position of the Philistines, worrying about the effect of Samson's foxes. See on Ecc. 7:26

8:6 God’s word is to be the seal upon our heart:

Deuteronomy 11:18	Song 8:6
"Lay up these words in your heart	"Set me (the bridegroom, Jesus, the Word) as a
. . . and bind them for a sign upon (thee)"	seal upon thine heart"
“Bind (these words) for a sign upon your hand".	"A seal upon thine arm"