Poole on Revelation 5:6: The Lion and the Lamb!
Verse 6: And I beheld, and, lo, in the midst of the throne and of the four beasts, and in the midst of the elders, stood (Is. 53:7; John 1:29, 36; 1 Pet. 1:19; Rev. 13:8; 5:8, 12) a Lamb as it had been slain, having seven horns and (Zech. 3:9; 4:10) seven eyes, which are (Rev. 4:5) the seven Spirits of God sent forth into all the earth.
[Behold in, etc., ἐν μέσῳ τοῦ θρόνου, etc.] In the midst of the throne (as if in the bosom of God, as One most dear to Him [Cotterius]: That He stands before the throne denotes that He ascended into heaven, and appears before God, and intercedes for us [Cocceius]; and sits at the right hand of God [Cocceius, Cluverus, Durham], and is a sharer in the Divine glory and power, Hebrews 1:3 [Cluverus]) and of the four living Creatures, and in the midst of the Elders (Erasmus). For by their seats the throne was surrounded (Cluverus). It denotes the presence of Christ in His Church (Durham, similarly Cluverus), in accordance with Matthew 28:20 (Cluverus). Here He appears in the middle position among the Apostles and Presbyters, undoubtedly so that He might be an example to the latter and to the former (Grotius). That, standing between the throne and the living creatures, etc., denotes His administration between God and the Church, towards both (Forbes); or His mediatorial office, by which He makes, undertakes, and introduces peace (Cocceius).
[A Lamb] Not of common note (Forbes), Paschal (Cluverus, thus Forbes). Thus Christ is called on account of innocence (Menochius), patience, and gentleness (Zegers, Piscator, Menochius, thus Durham), towards His people (Durham); and on account of His sacrifice (Menochius, similarly Durham).
[Standing] That is, living. This pertains to His resurrection (Grotius, similarly Cluverus out of Andreas Cæsarius, Ribera). Others: standing, as victor (Pareus), or, as ready (Tirinus, Cluverus, Durham), to help His own (Cluverus, similarly Durham, Tirinus), Hebrews 4:16 (Cluverus), to intercede for them after the likeness of an advocate (Tirinus out of Augustine).
[As, etc., ὡς ἐσφαγμένον] Σφάττειν and σφάζειν, to slaughter, are words proper to sacrifices, Genesis 22:10; Exodus 12:6; 29:11, 16, 20, and often elsewhere, and in Revelation 13:8 (Grotius). As slaughtered (Montanus), that is, a sacrifice killed by having its throat cut (Cotterius). A symbol of the suffering of the cross (Piscator). As one who had been sacrificed (Grotius, thus Mede), that is, wet with blood and displaying wounds (Grotius); bearing the signs and wounds of death (Mede’s Works 545, similarly Ribera, Pererius, Menochius, Pareus), by which He had merited the opportunity to do this (Mede’s Works 545, similarly Durham). By this expression it declares that the efficacy of His death before God is ever present and eternal (Forbes). Others: He says as one slain, because He arose so quickly that He was able to be reckoned by men as if He had not been dead (Ribera out of Ambrose and Arethas and Haymo). Or, as does not here denote similitude, but reality, as in in John 1:14; 2 Corinthians 3:18; 5:20 (Ribera).
And I beheld; hearing the mention of a Lion of the tribe of Judah, he looks about wistly to see if he could see any justifying that representation. And, lo, in the midst the throne and of the four beasts, and in the midst of the elders, stood a Lamb: instead of a Lion he seeth a Lamb; Christ Jesus, called a Lamb by this apostle, John 1:29, 36, and very often in this book; a Lamb, for whiteness and innocency, 1 Peter 1:19, for meekness and patience, Acts 8:32, but here with reference to the paschal lamb. As it had been slain; for he appears wounded and pierced, as if he had been slain; and to show that he was equal with the Father, he appears in the midst of the throne; and in the midst of the elders, and of the four living creatures, to show his presence with his church and ministers, Matthew 28:20, and his walking (as was said, Revelation 2:1) in the midst of is churches, which were the golden candlesticks there mentioned.
[Having seven horns] That is, royal power (Cluverus, similarly Zegers), which horns signify, Psalm 89:24; 92:10; 132:17; Daniel 8:20, 21; Zechariah 1:18 (Cluverus); or, enormous strength (Grotius, similarly Piscator, Cotterius, Durham, Hammond, Forbes), for subduing enemies, Psalm 75:5, 10 and elsewhere. Thus below, the Kings that were sustaining the Roman Empire are called the horns of the Roman Empire. A remarkable thing, a Lamb with horns, even indeed with seven horns. The greatest strength after the greatest patience (Grotius). Horns sometimes signify only strength and excellence, as in Psalm 18:2; 22:21; Lamentations 2:3, 17 (Durham).
Having seven horns; he appeareth now with seven horns, which are members in which the beasts’ strength, power, and beauty is much seen, to denote his glory and beauty, and the power he had now received to offend and conquer all his enemies.
[And eyes (that is, colors, after the Hebrew custom, as in Revelation 4:6 [Grotius]) seven] It denotes His perfect wisdom or knowledge (Forbes, similarly Cluverus, Durham), or, providence (Piscator).
[Which are (namely, in a mystery, as in Revelation 4:5 [Grotius]) the seven spirits, etc.] That is, Symbols of the seven spirits, that is, of all the spiritual gifts (Piscator). As many ways as God makes use of in governing the World, so many ways Christ makes use of in governing, protecting, and avenging the Church (Grotius).
And seven eyes, which are the seven Spirits of God; and with seven eyes, which were the seven Spirits of God, mentioned Revelation 1:4; 4:5; endued with the Spirit of God, (which is also called his Spirit,) not given to him by measure. Sent forth into all the earth; which spiritual gifts and perfections he exerciseth over all the earth, both with relation to his church, and to his church’s enemies.
 Greek: καὶ εἶδον, καὶ ἰδού, ἐν μέσῳ τοῦ θρόνου καὶ τῶν τεσσάρων ζώων, καὶ ἐν μέσῳ τῶν πρεσβυτέρων, ἀρνίον ἑστηκὸς ὡς ἐσφαγμένον, ἔχον κέρατα ἑπτὰ καὶ ὀφθαλμοὺς ἑπτά, οἵ εἰσι τὰ ἑπτὰ τοῦ Θεοῦ πνεύματα τὰ ἀπεσταλμένα εἰς πᾶσαν τὴν γῆν.  See Hebrews 7:25.  Genesis 22:10: “And Abraham stretched forth his hand, and took the knife to slay (לִשְׁחֹט; σφάξαι, in the Septuagint) his son.”  Exodus 12:6: “And ye shall keep it up until the fourteenth day of the same month: and the whole assembly of the congregation of Israel shall kill itוְשָׁחֲט֣וּ אֹת֗וֹ כֹּ֛ל קְהַ֥ל) עֲדַֽת־יִשְׂרָאֵ֖ל; καὶ σφάξουσιν αὐτὸ πᾶν τὸ πλῆθος συναγωγῆς υἱῶν Ἰσραὴλ, in the Septuagint) in the evening.”  Exodus 29:11: “And thou shalt kill (וְשָׁחַטְתָּ; καὶ σφάξεις, in the Septuagint) the bullock before the Lord, by the door of the tabernacle of the congregation.”  Exodus 29:16: “And thou shalt slay (וְשָׁחַטְתָּ; καὶ σφάξεις, in the Septuagint) the ram, and thou shalt take his blood, and sprinkle it round about upon the altar.”  Exodus 29:20a: “Then shalt thou kill (וְשָׁחַטְתָּ; καὶ σφάξεις, in the Septuagint) the ram, and take of his blood, and put it upon the tip of the right ear of Aaron…”  Revelation 13:8: “And all that dwell upon the earth shall worship him, whose names are not written in the book of life of the Lamb slain (ἐσφαγμένου) from the foundation of the world.”