Claimable.cs

var asset = new AssetTypeNative();
var source = KeyPair.FromSecretSeed("Your source key");

var claimant = new Claimant
{
    Destination = destination,
    Predicate = ClaimPredicate.Not(ClaimPredicate.BeforeRelativeTime(new xdrSDK.Duration(new xdrSDK.Uint64((UInt64)TimeSpan.FromHours(7.0).TotalSeconds))))
};

var operation = new CreateClaimableBalanceOperation.Builder(asset, "123.45", new[] { claimant })
                    .SetSourceAccount(source)
                    .Build();