Book of Hosea Chapter 4 Vs. 15

 The Lord Accuses Israel

Though thou, Israel, play the harlot, yet let not Judah offend; and come not ye unto Gilgal, neither go ye up to Bethaven, nor swear, The LORD liveth. Hos. 4:15

let not Judah... Israel of the northern kingdom was past turning back to God, so He advised Judah to take a lesson from this and not offend Him or go past repentance and the place of surrender to Him. History records that Judah did not learn her lesson though; 133 years after the fall of Samaria she also was destroyed (2Kgs. 17-25).

and come not... Judah was commanded not to go up to Gilgal where Jeroboam had erected an idolatrous temple, and where they had rejected Jehovah as King many years before. The idea was that they must not go after idols and reject Him. Gilgal, Between Jordan and Jericho in the area of Samaria, this was once a holy place to God (Jos. 5:10-15; 1Sam. 10:8; 15:21), afterwards desecrated by idol worship (9:15; 12:11; Amos 4:4; 5:5).

neither go ye... Judah was also told not to go up to Beth-aven. This word, meaning house of naught, was substituted for Beth-el, house of God, in the place where Jeroboam set up the worship of a golden calf (1Kgs. 12:28-33; 13:1; Amos 3:14). Beth-aven, Judah was to stay away from Israel’s centers of false worship, including Beth-aven (“house of wickedness/deceit”). This was a deliberate substitution for the name Bethel (“house of God”), once sacred to God (Gen. 28:17, 19), but made by Jeroboam a place to worship calves (1Kgs. 12:28-33; 13:1; Jer. 48:13; Amos 3:14; 7:13).

Israel got into this type of sin long before Judah did. In fact, Israel went into Assyrian captivity more than a hundred years before Judah was taken captive by Babylon. Jeroboam had set up a calf to worship in Beth-haven. Gilgal had become a place of worship of false gods. God did not want them mingling with those of Judah, for fear Judah would pick up their idolatry.

Judah was now warned to avoid the sins of her sister Israel. This need not mean that the people of Judah were in the habit of visiting northern cultic sites, such as Gilgal (cf. Hos. 9:15) and Beth Aven. Mays explains, “The exhortation… is simply bitter condemnation of their cult… for the ears of those who did worship in them” (Hosea, p. 77). The threefold warning (Do not go… do not go… do not swear) is a rhetorical device designed to accentuate Israel’s guilt. To associate oneself with Israel’s false, hypocritical worship would be contaminating. Even Bethel (lit., “house of God”), the site of Jacob’s dream (Gen. 28:10-19), had become “Beth Aven” (lit., “house of wickedness”; cf. Hos. 10:5; Amos 5:5) because of the religious practices conducted there (1Kgs. 12:28-30; 2Kgs. 10:29; 23:15; Amos 4:4). In the midst of this idolatrous, immoral worship the Israelite's even had the audacity to employ the Lord’s name in oaths. The Law commanded Israel to swear by the Lord’s name (Deut. 6:13; 10:20). However, to make a semblance of devotion to the Lord while serving other gods was the grossest hypocrisy.