Leviticus 26:21
And if ye walk contrary unto me, and will not hearken unto me; I will bring seven times more plagues upon you according to your sins. And if ye walk contrary unto me, and will not hearken unto me; I will bring seven times more plagues upon you according to your sins.
Leviticus 26:3-28 lays out the covenant blessings for obedience and the curses for rejecting God's requirements, where obedience brings rain in season, fruitful land, abundance, safety from enemies, and God's presence dwelling among His people, while disobedience brings the opposite. To walk contrary to God is to walk contrary to His will and way and to do despite to His grace. In this setting, walking contrary to a person can also mean opposing or testing him through adversity.
If His people persist in going against Him and refuse to hearken and obey, He will bring upon them seven times more plagues according to their sins, with punishment increased in proportion to sin. The threatened judgments include being scattered among the heathen with a sword drawn after them, with the land left desolate and the cities waste, and with failed crops and strength spent in vain. God permits such judgments to fall so that the nations may know themselves to be but men.
Walking contrary to God and grieving the Holy Spirit through sin can cost the soul, separating the sinner from God and at last from heaven. Persisting in disobedience and departing from God can leave a person under Satan's control. The history of Israel stands as the demonstration of what follows refusing God's warnings and persisting in disobedience. The warning stands as an admonition to those living at the end of the world, where those who reject God's message may provoke Him to condemn them and to withdraw His prosperity.
The same warning applies to mismanagement in God's work, showing that God's displeasure will come when His people reject His direction and that changes are needed. It applies also to those who selfishly withhold their means from God's work, in that losses may scatter the resources they refuse to use for His glory, although some may suffer no such visible loss. God continues His dealing through increasing affliction until the person recognizes that God's hand is dealing with him. The chapter containing the verse is therefore to be read carefully and its warnings taken seriously, for God may bring people over the same ground. Walking contrary includes losing spiritual discernment and doing harm by false representation, such as making an untrue report that leaves a false and unhelpful impression on another mind, even against one who has tried in every way to be a friend, and such a course brings sorrow and grief.