"The Canaanites had filled up the measure of their iniquity, and the Lord would no longer bear with them. His protection being removed, they would be an easy prey. By the covenant of God the land was ensured to Israel. But the false report of the unfaithful spies was accepted, and through it the whole congregation were deluded. The traitors had done their work. If only the two men had brought the evil report, and all the ten had encouraged them to possess the land in the name of the Lord, they would still have taken the advice of the two in preference to the ten, because of their wicked unbelief. But there were only two advocating the right, while ten were on the side of rebellion. PP 390.1"
"But in the fourth generation they shall come hither again: for the iniquity of the Amorites is not yet full."
Both passages discuss the concept of a nation's iniquity reaching its limit, leading to judgment. EGW connects the Canaanites' situation to the delay mentioned in Genesis 15:16 regarding the Amorites.
"The unfaithful spies were loud in denunciation of Caleb and Joshua, and the cry was raised to stone them. The insane mob seized missiles with which to slay those faithful men. They rushed forward with yells of madness, when suddenly the stones dropped from their hands, a hush fell upon them, and they shook with fear. God had interposed to check their murderous design. The glory of His presence, like a flaming light, illuminated the tabernacle. All the people beheld the signal of the Lord. A mightier one than they had revealed Himself, and none dared continue their resistance. The spies who brought the evil report crouched terror-stricken, and with bated breath sought their tents. PP 390.2"
"But all the congregation bade stone them with stones. And the glory of the Lord appeared in the tabernacle of the congregation before all the children of Israel."
Both passages describe the congregation attempting to stone Caleb and Joshua, and the glory of the Lord appearing in the tabernacle.
"Moses now arose and entered the tabernacle. The Lord declared to him, “I will smite them with the pestilence, and disinherit them, and will make of thee a greater nation.” But again Moses pleaded for his people. He could not consent to have them destroyed, and he himself made a mightier nation. Appealing to the mercy of God, he said: “I beseech Thee, let the power of my Lord be great according as Thou hast spoken, saying, The Lord is long-suffering, and of great mercy.... Pardon, I beseech Thee, the iniquity of this people according to the greatness of Thy mercy, and as Thou hast forgiven this people, from Egypt even until now.” PP 390.3"
"And Moses said unto the Lord, Then the Egyptians shall hear it, (for thou broughtest up this people in thy might from among them;) And they will tell it to the inhabitants of this land: for they have heard that thou Lord art among this people, that thou Lord art seen face to face, and that thy cloud standeth over them, and that thou goest before them, by day time in a pillar of a cloud, and in a pillar of fire by night. Now if thou shalt kill all this people as one man, then the nations which have heard the fame of thee will speak, saying, Because the Lord was not able to bring this people into the land which he sware unto them, therefore he hath slain them in the wilderness. And now, I beseech thee, let the power of my Lord be great, according as thou hast spoken, saying, The Lord is longsuffering, and of great mercy, forgiving iniquity and transgression, and by no means clearing the guilty, visiting the iniquity of the fathers upon the children unto the third and fourth generation. Pardon, I beseech thee, the iniquity of this people according unto the greatness of thy mercy, and as thou hast forgiven this people, from Egypt even until now. And the Lord said, I have pardoned according to thy word:"
The EGW passage directly quotes and paraphrases Numbers 14:13-20, particularly Moses' intercession and God's attributes.