'Legs' signify the exteriors of the natural man.

(Odkazy: Arcana Coelestia 10050)

241. The first living creature was like a lion. (4:7) This symbolizes the Divine truth of the Word in respect to its power.

A lion symbolizes truth in its power, here the Divine truth of the Word in respect to its power, as can be seen from the power of the lion, which surpasses that of every other animal on the earth. It can be seen as well from lions in the spiritual world and the fact that they are images representative of the power of Divine truth. And it can be seen, too, from the Word, in which lions symbolize Divine truth in its power. The nature of the power of Divine truth in the Word may be seen in The Doctrine of the New Jerusalem Regarding the Sacred Scripture 49, and in the book Heaven and Hell, nos. 228-233.

So it is that Jehovah or the Lord is likened to a lion, and also called a lion, as in the following passages:

A lion has roared! Who does not fear? The Lord Jehovih has spoken! Who does not prophesy? (Amos 3:8)

I will not turn back to destroy Ephraim... They shall walk after Jehovah. He roars like a lion. (Hosea 11:9-10)

As a lion roars, and a young lion..., so Jehovah... will come down to fight upon Mount Zion... (Isaiah 31:4)

Behold, the Lion of the tribe of Judah, the Root of David, has prevailed... (Revelation 5:5)

Judah is a lion's whelp... He bowed down, he lay down... as an old lion. Who rouses him? (Genesis 49:9)

[2] A lion in these passages describes the power of the Divine truth emanating from the Lord. Roaring symbolizes His speaking and acting with power against the hells, which try to carry off a person as a lion does its prey, but from which the Lord rescues him. To bow down means to put Himself into a condition of power. Judah, in the highest sense, symbolizes the Lord (nos. 96, 266).

(The angel) cried with a loud voice, as when a lion roars. (Revelation 10:3)

He bows down, he lies down... as an old lion. Who rouses him? (Numbers 24:9)

Lo, the people rises like an old lion, and like a young lion lifts itself up. (Numbers 23:24)

This last declaration is said of Israel, which symbolizes the church, whose power, which lies in Divine truths, is thus described.

So likewise:

The remnant of Jacob shall be... in the midst of... peoples, like a lion among the beasts of the forest, like a young lion among flocks of sheep... (Micah 5:7-8)

And so on in many other places, as in Isaiah 11:6; 21:6-9; 35:9; Jeremiah 2:15; 4:7; 5:6; 12:8; 50:17; 51:38; Ezekiel 19:3, 5-6; Deuteronomy 33:20.