Is the Hebrew word for pitch the same word as atonement?
Yes. The Hebrew word for pitch is the same Hebrew word as atonement. In the flood account, the pitch sealing the ark's boards pictured the atoning effect, just as blood seals out judgment so it cannot touch us, and the pitch sealed out the floodwaters.
Les explains that God instructed Noah to seal the ark with pitch, a tar, so it would not leak during the flood. He points out that the same Hebrew word for pitch is also the Hebrew word for atonement. The pitch between the boards had a sealing, atoning effect: just as the pitch sealed out the waters of the flood, the blood of Christ seals out judgment so it can never touch the believer. Les says this theme runs through Scripture—we are secure not because of what we do or deserve, but because we have placed our faith in the blood of Christ and His resurrection.