Construction and Building

Building and construction are everywhere in this poem. It's about an altar, but also about all the steps the speaker has taken to build his altar. An altar has been "reared." That altar is "cemented" (i.e., held together) with tears. No tools have been used, and all the "stones" that make up the altar have been left just the way the master stonemason, God, has made them. So what's up with all this building, you ask? Well, the act of building is the poem's metaphor for the process of praising God in the form of sacrifice, and for the process of poetic creation. The speaker builds an altar to God and offers himself, but he also builds a poem that, he hopes, will praise God even after he has died.

• Lines 1-2: The speaker refers to himself in the third person and describes the altar being reared (it is broken but "cemented" with tears). The altar is both the poem itself and the speaker's heart (a symbol, in fact, for his entire being). 
• Line 3: "Frame" is here a verb used to describe God's act of creation. Later in the poem it will be used as a noun to refer to the poem itself. If God "frames" things, and the speaker also makes a "frame" (the poem), then the speaker himself is kind of like a mini-God or mini-creator.
• Line 4: The speaker alludes to Exodus 20:25 and says that all the pieces of his altar have been assembled just the way they are (they haven't been altered or manipulated in any way). This allusion underscores the speaker's strict religious principles and is a metaphor for the act of offering oneself to God just as one is (i.e., imperfect, sinful, "broke," etc.).
• Lines 5-6: The speaker uses a metaphor here to compare the heart to a stone. These lines reiterate the point made in lines 1-2; namely, that an altar can be constructed out of the pieces of one's heart. 
• Lines 7-8: God is here compared to a stonemason of some kind. This metaphor essentially says that the human heart could only have been created by God. It is also the speaker's way of showing his adherence to biblical rules. He's making an altar out of his heart, and the only builder or stonemason who has touched that heart is God. 
• Line 12: The word "frame" here refers to the poem. The word echoes God's act of "framing" in line 3, and thus suggests that the creation of poetry is similar to an act of biblical creation. 
• Lines 13-14: We encounter the word "stones" again, and this time they are a metaphor for the lines of the poem itself. The speaker is wondering what will happen when he dies, and he hopes that his poem will continue to "speak" for him after that happens.